The present invention relates to a film inspecting apparatus, in particular, a film inspecting apparatus using a scanning type probe microscope.
For a hard disc and semiconductor device, a thin film, such as a dielectric film, has been often used. In forming the thin film, surface roughness and quality of the thin film are important elements, and control of the film quality is important in controlling a quality of the semiconductor device, which influences the precision and yield of the semiconductor. For example, in case a wiring portion of the semiconductor device is formed of a thin film, electrical characteristics thereof greatly vary according to the surface roughness and quality of the thin film.
Especially, as the semiconductor device is finely structured, the surface roughness and particle size required for the surface of the thin film also become finer. Therefore, even if the thin film has the surface roughness and particle size which have not conventionally influenced the quality of the semiconductor device, proper attention has to be paid thereto.
Heretofore, a roughness measuring gauge for measuring roughness of an object's surface has been known. However, a range of the roughness measured by the roughness measuring gauge is large, and the roughness measuring gauge is not sufficient for measuring an unevenness of the surface of the thin film in the order of a nanometer.
Also, generally, a scanning type probe microscope (SPM), such as an interatomic force microscope (AFM) and a scanning type tunnel microscope (STM), has been known. However, in such a scanning type probe microscope, only a shape of the surface can be obtained as three-dimensional data, wherein the surface shape can be obtained as a continuous uneven shape, and the particle state for forming the thin film surface can be recognized.
Therefore, it is impossible by the scanning type probe microscope to recognize individual particles on the surface of the thin film in order to inspect the sizes and states of the particles.
Thus, any useful means for inspecting the fine roughness and the particle state on the surface of the thin film have not substantially been presented, and a film inspecting apparatus for measuring such fine roughness and particle state of the thin film has been strongly requested.
Accordingly, an object of the invention is to obviate the problems of the prior art and to provide a film inspecting apparatus, wherein fine roughness and particle state on a surface of a thin film can be obtained and inspected.
Further objects and advantages of the invention will be apparent from the following description of the invention.